Amenorrhea

Amenorrhea is the absence of menstrual cycles.

Amenorrhea is called primary when a woman has not started to menstruate by the age of 16 years, while secondary amenorrhea refers to the abnormal cessation of menstruation in a woman who previously has had menstrual cycles.1 In amenorrheic women, the levels of female reproductive hormones are not sufficient to stimulate menstruation. This condition is sometimes associated with malnutrition, such as that which occurs in anorexia nervosa, or with extreme exercise, which puts excessive nutritional and other demands on the body.2 3 An association between stress and amenorrhea has also been demonstrated.4 Amenorrhea may also result from potentially serious disorders of the ovaries, the hypothalamus, or the pituitary gland; therefore, a physician should always evaluate chronic absence of menstrual cycles. Prolonged amenorrhea can result in early bone loss and increased risk of osteoporosis.5 Amenorrhea occurs naturally in women who are breast-feeding,6 but in these circumstances it does not put the bones at risk.

It has long been known that extreme dietary restriction can cause amenorrhea.8 9 When such restriction is due to eating disorders, such as anorexia and bulimia,10 professional treatment is necessary. Athletic amenorrheic women may have low intakes of calories and other nutrients, and there are reports of some athletes resuming menstruation after adding to their diet a daily nutritional beverage containing additional calories, protein, carbohydrate, fat, vitamins, and minerals.11 12 However, these women also decreased their exercise intensity, which likely contributed to normalization of their menstrual function.

When compared with women who menstruate regularly, women who menstruate infrequently or not at all often have lower dietary intakes of fat (especially saturated fat), protein, and total calories, as well as a greater proportion of carbohydrate and fiber in their diet.13 14 15 In preliminary studies of normal-weight women with no obvious eating disorders, women who experienced amenorrhea had diets described as “close to normal” but significantly low in fat. These women had lower percentages of body fat as well.16 17 In one of these studies, regular menstruation returned in women who increased their fat intake and percentage of body fat to normal over four months.18

Specific diets may be associated with increased risk of amenorrhea. A strict raw foods diet was found in one preliminary study to be strongly associated with weight loss and amenorrhea.19 Vegetarians have been studied for their susceptibility to amenorrhea, but the results so far have been inconsistent.20 Vegetarian diets tend to be rich in the antioxidant nutrients known as carotenes. Women with excessive carotene levels in their blood appear to be at higher risk of amenorrhea than women with normal levels,21 22 and, while research has not shown high carotene levels to directly cause amenorrhea, they may constitute a contributing factor.23 In one preliminary study, women with high levels of both carotenes and amenorrhea had predominantly vegetarian diets, and reducing dietary intake of carotenes led to lower carotene levels and improvement in their amenorrhea.24 Women vegetarians often rely heavily on soy foods as sources of protein, and a number of studies have found that increasing dietary intake of soy reduces levels of estrogen and progesterone in premenopausal women,25 26 27 28 29 30 although some studies have not found these changes.31 32 Changes in menstrual cycles were not consistent in these studies, and none found an increase in missed menses with high-soy diets. The only well-controlled comparison study found that the number of cases of amenorrhea among healthy, stable-weight vegetarian women was not different from that of healthy, stable-weight non vegetarian women.33 The authors of this study speculated that, after reviewing all of the evidence, a vegetarian diet is likely not to contribute to amenorrhea.

Lifestyle changes that may be helpful for amenorrhea

Moderate exercise has many benefits to the overall health of premenopausal women, but intensive or excessive exercise can contribute to amenorrhea and increase the risk of early bone loss due to detrimental effects on hormone balance.34 Exercise typically increases bone density, but a study of dancers with amenorrhea found that bone density measurements remained below normal for the entire two-year duration of the study.35 The demands placed upon women performers and athletes are believed to contribute to the high incidence of eating disorders among them. This, along with the increased physical and nutritional demands of intensive exercise, can lead to nutrient deficiencies and lowered body-fat percentages that may contribute to amenorrhea and bone loss in women athletes.36 37 38 Running and ballet dancing are among the activities most closely associated with amenorrhea,39 with as many as 66% of women long-distance runners and ballet dancers experiencing amenorrhea.40 Among women bodybuilders in one study, 81% experienced amenorrhea, and many had nutritionally deficient diets.41 While some amenorrheic athletes have been reported to resume menstruation after adding one day of rest per week and consuming a daily nutritional beverage containing additional calories, protein, carbohydrate, fat, vitamins, and minerals,42 43 no controlled trials have investigated this approach.

Hormonal changes associated with breast-feeding prevent menstruation in healthy women.44 The duration of this interruption in menstruation, known as lactational or postpartum amenorrhea, depends on many factors, including the nutritional health of the mother. Poor maternal nutritional status has been associated with longer periods of lactational amenorrhea in developing countries45 46 47 48 as well as in Great Britain among poor nursing women.49 Better maternal nutritional status was found to be associated with shorter lactational amenorrhea in well-nourished nursing mothers in the United States.50 When malnourished nursing mothers are given food supplements, the length of lactational amenorrhea can be shortened, according to preliminary studies.51 However, one controlled trial found dietary supplementation with skim milk did not shorten the duration of amenorrhea in well-nourished nursing mothers.52 Although prolonged lactational amenorrhea prevents another pregnancy, it has not been shown to result in permanent bone loss.53

Excessive stress causes the body to produce increased amounts of the adrenal hormone cortisol, and several studies have linked high cortisol levels to low levels of reproductive hormones and to amenorrhea.54 55 56 In one study, amenorrheic women showed a greater increase in cortisol in response to stress than did women with normal menstrual cycles.57 No research has been done to evaluate stress reduction interventions for the treatment of amenorrhea.

Smoking may contribute to amenorrhea. A survey study found that young women smoking one pack or more per day were more likely to be amenorrheic than other women.58 However, whether smoking cessation will normalize menstrual function in amenorrheic women is unknown.

Nutritional supplements that may be helpful for amenorrhea

Oral, micronized progesterone (200 to300 mg per day) has been shown in at least one double-blind trial to successfully induce normal menstrual bleeding in women with secondary amenorrhea.59 Use of this natural hormone should always be supervised by a doctor.

A preliminary trial showed that bone loss occurred over a one-year period in amenorrheic exercising women despite daily supplementation with 1,200 mg of calcium and 400 IU of vitamin D.60 In a controlled study of amenorrheic nursing women, who ordinarily experience brief bone loss that reverses when menstruation returns, bone loss was not prevented by a multivitamin supplement providing 400 IU of vitamin D along with 500 mg twice daily of calcium or placebo.61 Despite the lack of evidence that calcium and vitamin D supplements alone are helpful to amenorrheic women, they are still generally recommended to prevent the added burden of calcium and vitamin D deficiency from further contributing to bone loss.62 Amounts typically recommended are 1,200 to 1,500 mg calcium and 400 to 800 IU vitamin D daily.

Acetyl-L-carnitine is an amino acid that may have effects on brain chemicals and hormones that control female reproductive hormones. In a preliminary trial, 2 grams daily of acetyl-L-carnitine was given to amenorrheic women who had either low or normal blood levels of female hormones. Hormone levels improved in the women with low initial levels, and half of all the women resumed menstruating within three to six months after beginning supplementation.63 Controlled trials are needed to confirm these promising results.

Vitamin C alone, at 400 mg daily, had no effect on amenorrhea in one preliminary trial, although it was associated with the return of ovulation in some women who were menstruating regularly but not ovulating. In a second phase of the trial, the same amount of vitamin C was combined with a drug that affects female hormone levels, and this combination was associated with return of ovulation in almost half of amenorrheic women who had not benefited from the drug alone.64 More studies of the effect of vitamin C on amenorrhea are needed.

Prolactin is a hormone that may be elevated in some cases of amenorrhea. A preliminary trial of 200 to 600 mg daily of vitamin B6 restored menstruation and normalized prolactin levels in three amenorrheic women with high initial prolactin levels; however, 600 mg daily of vitamin B6 had no effect on amenorrheic women who did not have high prolactin levels.65 A number of other small, preliminary trials have not demonstrated an effect of either oral or injected vitamin B6 on prolactin levels,66 67 68 69 70 and they also have reported inconsistent effects on restoring menstruation.71 72 73 Larger, controlled trials are needed to better determine the usefulness of vitamin B6 in amenorrhea.

While zinc is known to be important for many aspects of reproductive function, little research has investigated its role in amenorrhea.74 In a controlled study of intense exercisers, zinc deficiency was equally common between amenorrheic and menstruating exercisers.75 More research is needed.

Are there any side effects or interactions with amenorrhea?

Refer to the individual supplement for information about any side effects or interactions.

Herbs that may be helpful for amenorrhea

Blue cohosh is a traditional remedy for lack of menstruation. It is considered an emmenagogue (agent that stimulates menstrual blood flow) and a uterine tonic. No clinical trials have validated this traditional use.

Other herbal emmenagogues traditionally regarded as stimulating absent or diminished menses are motherwort, rue, partridge berry, and yarrow. None of these herbs has undergone modern clinical trials to determine their efficacy. All emmenagogues should be avoided in pregnancy, as they may possibly cause a spontaneous abortion.

In herbal medicine, Vitex agnus-castus (chaste tree) is sometimes used to treat female infertility and amenorrhea.76 Elevation of prolactin can be a cause of amenorrhea, and vitex has been shown in animals to reduce elevated prolactin levels.77 In a controlled trial, prolactin production was normalized in women with high prolactin levels after three months of treatment with vitex.78 Vitex has also been found to raise levels of luteinizing hormone and subsequent progesterone levels in women with luteal phase defect—a condition that can also lead to menstrual cycle abnormalities, including amenorrhea.79 To date, only one small preliminary trial has studied the effects of vitex on amenorrhea. This study found that ten of fifteen women with amenorrhea began having a normal period after taking 40 drops of a liquid vitex preparation once daily for six months.80 Further research is needed to determine what role vitex may play in the management of amenorrhea.

Are there any side effects or interactions with amenorrhea?

Refer to the individual herb for information about any side effects or interactions.

Holistic approaches that may be helpful for amenorrhea

In a number of preliminary trials,81 82 83 acupuncture has been shown to induce ovulation in women with disorders involving lack of ovulation. Preliminary studies show that levels of estrogen and progesterone, as well as levels of the related hormones LH (luteinizing hormone) and FSH (follicle-stimulating hormone), may all be affected by acupuncture.84 85 Few studies have looked at the use of acupuncture for treatment of amenorrhea, but one preliminary trial found it helpful for women who have widely separated menstrual cycles.86 In one controlled trial, amenorrheic women showed a trend toward normalizing hormone levels following acupuncture.87